i don't know how much experience you have with modding, so i'm just going to lay this out in baby-steps, as if i was explaining it to an absolute beginner. don't be offended if some steps seem really obvious.

highlight the "blaster pistol" line after "lang_english" and hit backspace. name it what you like. DO NOT change the top "blaster_pistol" after "reference". leave that how it is. only change what is in the quotes. make it DL-44 or whatever you wanted.

now, save the file, and exit.

cut the file from your desktop and paste it back into Pakscape, replacing the old "MENUS" file. Save the folder in Pakscape and exit.